[Ips-dhfpr] ASWFC Daily HF Prop Report - 17 April 25 issued 2331 UT on 17 Apr 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/17 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (17 APRIL) 
Date   T index  Conditions    
17 Apr    99    Fair           

Flares: none.

MUFs:
   Cocos Island Region:
      Enhanced by 20% during local day.
      Enhanced by 35% during local night.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   Southern Australian Region:
      Depressed by 30% during local day.
      Depressed by 25% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 25% over the UT day.

PCA Event : No event.

Monthly T index:
Month  T index
Mar      126
Apr      115
May      113


2. FORECAST (18 APRIL - 20 APRIL)
Date   T index  Conditions       MUFs                              
18 Apr   105    Normal-fair      Depressed 10 to 20%/near predicted 
                                 monthly values
19 Apr   115    Normal-fair      Depressed 10 to 20%/near predicted 
                                 monthly values    
20 Apr   120    Normal           Near predicted monthly values   

COMMENT: ASWFC HF Communications Warning 40 was issued on 16 
April and is current for 17-19 Apr. Maximum usable frequencies 
(MUFs) in the Australian region were depressed by 30% in the 
southern region, but near predicted values to 15% enhanced in 
the northern region. Despite geomagnetic storm activity the day 
prior, HF conditions were generally non-degraded throughout the 
local day and night. MUFs are expected to be depressed by 10-20% 
over 18-19 Apr, on an improving trend, and near predicted values 
by 20-Apr.

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For an explanation of some of the terms in this report, go to
https://www.sws.bom.gov.au, and follow links to Educational->
Glossary on Solar Terrestrial Terms.

Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au